New Data from Old Cores: Supplementing the Paleoceanographic Sedimentary Archive with Museum Collections.
Christine Garcia1, Hannah M Palmer2, Veronica Vriesman3, Tessa M Hill4, Peter D Roopnarine5, Marie Angel1 and Lillian Kennedy Pearson6, (1)California Academy of Sciences, Invertebrate Zoology and Geology, Institute for Biodiversity Science and Sustainability, San Francisco, CA, United States, (2)University of California Merced, Life & Environmental Sciences, Merced, CA, United States, (3)UC Davis, Earth and Planetary Sciences, Davis, CA, United States, (4)University California Davis, Earth and Planetary Sciences and Bodega Marine Laboratory, Davis, CA, United States, (5)California Academy of Sciences, Department of Invertebrate Zoology & Geology, Institute for Biodiversity Science and Sustainability, San Francisco, CA, United States, (6)University of Southern Mississippi, Division of Marine Science, Stennis Space Center, MS, United States
Abstract:
Paleoceanographic records provide a unique opportunity to understand how ecosystems have responded to rapid environmental change in the past, a topic of significant societal and scientific interest. Yet, there remains a substantial financial and temporal cost to collecting offshore cores, impeding access to this important environmental archive. The former microfossil collections of the Union Oil Company of California, reposited at the California Academy of Sciences, expand the geographic and depth range of material currently available for paleoceanographic analysis and lend new opportunities for insights into the marine sedimentary record of Cenozoic California. As part of NSF-supported collaborative research to document ecological changes in nearshore environments in Southern California, we isolated 43 offshore cores from the > 7,000 core collection and analyzed samples for foraminifera and metazoan composition.
Samples analyzed are from the Southern California Borderlands and west of Point Conception (33º to 35º N and 121º to 118º W). Importantly, these cores were collected at water depths (29-165.2 m) not typically sampled by deep sea drilling. This allows for comparisons between these records and the well-studied basins of the Southern California Borderlands, including the Santa Barbara Basin. Cores were collected between 1925-1982 CE and range in length from surface samples to 3541 mbsf. Planktic foraminifera are present in 56.4% of samples, benthic foraminifera are present in 64.4% of samples and metazoan shell fragments are present in 51.9% of samples. Intact metazoans are present in multiple samples, providing a valuable archive to study ecosystem change through time; we identify bivalves (in 13.8% of samples), gastropods (in 9.4% of samples), and echinoderm spines (in 10.4 % of samples). Through this project, we have identified, cataloged, and digitized microfossil samples collected along the California margin. All data generated under this work will be made digitally available to the public via online databases iDigBio and GBIF.
